Blackboard-eraser.



R. A. COSTELLO.

BLACKBOARD ERASER.

APPLICATION msn MN. 12. 1914.

Patented Sept. 21, 1915.

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RICHARD A. COSTELLO, 0F CHICAGO HEIGHTS, ILLINOIS.

BLACKBOARD-ERASER.

Specification of Letters Patent.

Patented Sept. 21, 1915.

- Application filed January 12, 1914. Serial No. 811,548.

To all whom t may concern Be it known that I, RICHARD A. COSTELLO, a citizen of the United States, residing at the city of Chicago Heights, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Blackboarddrasers, of which the following is a specification.

My invention relates to erasers which are used for removing chalk marks from blackboards and for similar purposes, and which are provided with rubbing members, one edge of which forms the erasing face, and the other edge of which is secured to the back or foundation piece.

The object of my invention is to provide a completely resilient and flexible eraser in which the several parts are securely fastened together; which shall be symmetrical in form and of an attractive general appearance; which is adapted to hold dust until removed, and which shall be susceptible of cheap construction by suitable machine operations.

The principles of my invention are illustrated in the drawings, in which- Figures 1 and 2 show respectively upper and lower perspective views; Fig. 3 is a cross section of Fig. 1 on the line 3-3, somewhat enlarged; Fig. 4L is a top view of Fig. 1, a portion of the finishing piece being removed.

Further describing my invention with reference to the drawing: 1 is a back or foundation piece, preferably of felt or some elastic material.

2-2 are rubbing members preferably of felt, having their upper edges 3, cut to a right angle with their sides so as to fit squarely o'n the underside of the foundation piece. The said strips are secured to the foundation piece by rows of stitching 4, which enter the strips a short distance below the upper edge and which are continued upwardly through the foundation piece. This stitching being made with proper tension will somewhat depress the sides of the rubbing strips along the line of the seam. A space 5 is thereby formed between the adjacent faces of each pair of rubbing strips, which will receive and hold a considerable amount of powdered chalk or other dust. Said accumulations may be readilyremoved by striking the face of the eraser against a resisting surface. lThe attachment of the rubbing strips to the back can best be made by making a number of the erasers in one piece, and then cutting them apart to proper length. A top or finishing piece 6, should then be applied for the double purpose of concealing the stitching by which the rubbing strips are attached to the foundation piece and of giving greater stability to the device as a whole. It is secured to the part already formed by rows of stitching 7, which pass completely around the edge of the finishing piece, and which go downwardly through the back or foundation piece, and the outside rubbing strips to the point of which the outside row of primary stitching enters the said strips. The said stitching 7 furthermore should engage the ends of the rubbing strips, thereby forming a stay and preventing the ends from working loose through continued use of the eraser.

I claim:

1. In an eraser, the combination with a foundation piece, of a plurality of rubbing strips squared at their upper edges and a plurality of rows of stitching one row on each side of each strip engaging the said strip at a point slightly removed from its squared edge and passing upwardly therethrough and through the foundation piece.

2. In an eraser, the combination with a foundation piece, of a plurality of rubbing strips squared at their upper edges and a plurality of rows of stitching one row on each side of each strip engaging the said strip at a point slightly removed from its squared edge and passing upwardly therethrough andthrough the foundation piece, a finishing piece above the foundation piece and a row of stitching passing through the finishing piece, the foundation piece and the outer part of the rubbing strips adjacent to their upper edges to secure the said elements in proper relative positions.

In witness whereof, I have hereunto subscribed my name, this 7th day of January, 1914, in the presence of two subscribing witnesses.

v RICHARD A. COSTELLO.

Witnesses:

C. K. CHAMBERLAIN, A. S. PHILLIPS.

Copies ot this patent may be obtained for five cents each, by addressing the Commissioner of latents, Washington, D. C. 

